code: def test_powerset__iter__():
      a = PowerSet(FiniteSet(1, 2)).__iter__()
      assert next(a) == S.EmptySet
      assert next(a) == FiniteSet(1)
      assert next(a) == FiniteSet(2)
      assert next(a) == FiniteSet(1, 2)
  
      a = PowerSet(S.Naturals).__iter__()
      assert next(a) == S.EmptySet
      assert next(a) == FiniteSet(1)
      assert next(a) == FiniteSet(2)
      assert next(a) == FiniteSet(1, 2)
      assert next(a) == FiniteSet(3)
      assert next(a) == FiniteSet(1, 3)
      assert next(a) == FiniteSet(2, 3)
      assert next(a) == FiniteSet(1, 2, 3)
  
file_path: sympy/sympy/sets/tests/test_powerset.py
imports: from sympy.core.expr import unchanged
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol
  from sympy.sets.contains import Contains
  from sympy.sets.fancysets import Interval
  from sympy.sets.powerset import PowerSet
  from sympy.sets.sets import FiniteSet
  from sympy.testing.pytest import raises, XFAIL
label_desc: Use image node_id 7 for calling a global function with example usage: test_powerset__iter__() without return types